Facsimile recording on dry electrolytic blanks



Feb. 4; 1964 H. R. DALTON 3,120,66

msmm: RECORDING on DRY mzcmowuc BLANKS Filed lay 24, 1957 HAROLD R. DALTON INVENTOR.

Wii? United States Patent York Filed May 24, 1957, Ser. No. 661,386 6 Claims. (Cl. 346-74) This invention relates to the art of electrolytic recording on dry electrolytic recording blanks, and more especially it relates to the recording of electric signals such as facsimile signals, on an electrolytic recording blank while the latter is. in an unmoistened state.

A principal object of the invention is to provide a novel method of making a permanent record of electric signals by acting on an electrolytic recording blank while the latter is in a dry or unmoistened state, to produce either a record in the blank in the form of surface colorations or in the form of perforations through the blank.

Another object is to provide a novel method of making a stencil by perforating an electrolytic cellulosic fibrous or paper blank while the latter is in a dry or unmoistened state.

A feature of the invention relates to a novel facsimile recording system employing a dry electrolytic paper recording blank, and a recording stylus which is energized by electric signals such as facsimile signals, and is also locally heated to a predetermined minimum temperature which enables the blank to be converted into a stencil record or a surface marked record while in the dry or unmoistened state.

A still further feature relates to the novel organization, arrangement, relative location and energization of parts which cooperate to provide an improved facsimile recording method and system.

While various method of recording on electrolytic blanks have been proposed heretofore, they have required that the blank be wet or moistened either over its entire surface at the time of recording, or that it include a material which when heated to a certain temperature becomes liquidized and changes from a normal non-conductor to a conductor. In either case when the blank was subjected to the recording currents from a signal-energized stylus electrode in contact with the blank, the blank was actually wet. I have devised a method whereby the electrolytic blank can be dry not only during storage, but also during recording, and does not require a liquid or moist condition in the blank in order to effect recording. In fact the blank can remain completely dry before, during and after recording, and requires no further treatment in the nature of a development or fixing process.

I have found that satisfactory and permanent recordings, either in the nature of surface markings, perforations, or both, can be effected by subjecting the recording stylus or electrode to a local heating operation whereby that stylus is maintained above a predetermined temperature at which the paper would ordinarily char, burn or discolor if heated to such a temperature over its entire surface. The paper itself is not heated and therefore can be used in a completely dry state for recording purposes. I have also found that if the dry paper as a whole is heated to such a temperature, not only are the recordings unsatisfactory, but the paper may even be deteriorated by the heat. However, by allowing the dry paper blank to be at normal or ambient temperature, and by heating, the stylus alone above the critical temperature to be described, satisfactory recordings can be made. With this method it is not necessary to use a special heat meltable constituent in the 2 paper, such as amides, which are required to be rendered liquid by the recording current. Accordingly the present invention enables any well known electrolytic recording paper to be satisfactorily recorded on, either bysurface markings or perforations, while the paper is in a dry or non-moistened state.

The single figure of the drawing shows schematically a recording system and method according to the invention.

The numeral 10 represents any well known source of electric facsimile signal voltages such as those produced by any well known telefacsimile transmitter machine. For example, this signal may be a direct current having a mean voltage of approximately 250 volts, and a mean current level of approximately 100 milliamperes. The voltage is varied above and below the mean value to represent the shade variations of the successive areas which are scanned by the scanning device of the facsimile transmitter 10.

The electric facsimile signal voltages are transmitted over a suitable channel or line represented by the numeral 11 and by the grounded return 12. Line 11 is connected to the recording stylus 13 which may be of any well known kind having a fine or needle point 14 which engages the surface of the recording blank 15 in which the signals are to be reproduced as a facsimile either in the form of discrete surface discoloration markings or as minute perforations through the blank 15, or both, while the blank 15 is cool or at ambient room temperature, and while it is dry. In order to complete the transmission circuit the blank 15 can be held by any suitable means against the grounded conductive platen or drum 16. Thus the member 16 may take the form of a cylindrical metal scanning drum of any well known facsimile receiver machine. Likewise, by well known means the stylus 14 is moved relatively to the drum 16, and therefore to blank 15, so that the stylus scans successive elemental areas of the blank 15 in synchronous with the scanning of the corresponding elemental areas of the subject matter being scanned by the facsimile transv mitter 10.

While in the drawing the polarity of the recording signals is shown as positive, in a direction considered through the blank towards the grounded platen 16, it will be understood that the polarity may be reversed. If desired, instead of using direct current facsimile signals, those signals may be in the form of an alternating current. For example they may consist of an audio frequency carrier which is modulated either in amplitude or in frequency by the facsimile voltages from the source 10.

The stylus 14 may be of any metal or alloy capable of withstanding continuous application of heat of from 400 F. to 700 F. without substantial deterioration, and also capable of withstanding to the desired extent the erosive effects of the facsimile signal currents flowing through the stylus to the platen 16. Examples of such stylus materials are platinum, tungsten, stainless steel, etc. Preferably, also, the material of the stylus is chosen with respect to the chemicals incorporated into the blank 15, so as to achieve a special marking effect such as a characteristic color development in the surface of the blank, resulting from the release of the metallic ions of the stylus acting as an anode, with the blank chemicals to produce the desired characteristic coloration marking effect on the blank. The blank 15 may be a dry paper sheet which has been impregnated with a chemical or chemicals such as urea formaldehyde resins, melamine formaldehyde resins, polyvinyl lattices, and the like, for imparting wet strength to the paper. The paper is also impregnated with any well known electrolytic salt or salts used in the electrolytic recording art. In addition the paper may include a special marking control agent-suchforexample' as a quinoline derivative which is capable of chemically reacting directly with the ions from the stylus 14 as an anode to effect a characteristic color marking of the surface of the blank. One of the advantages of such a blank is that it has an over-all whitish surface which remains white indefinitely except at those minute areas where its surface color has been changed by the recording .current acting thereon. For a detailed description of sucl'ia blank and method of manufacture reference may be had to my copending application Serial No. 618,ll9,-filed October 24, 1956.

In order to use such blanks with the conventional electrolytic facsimile recording methods, it is necessary that the blank at the instant of recording have a predetermined moisture content. For example in one known method the blank is passed through a moistening bath just before it reaches the recording point. In another known method the blank includes as a necessary constituent a special material which is normally dry or solid but which when heated becomes liquid and the blank then becomes electrically conductive so that it can be recorded on in the usual way. Both of these prior moistening or liquidizing operations are completely avoided according to the present invention. In other words, the blank 15 can be taken directly from its storage supply in dry or near zero moisture condition and applied to the drum '16 where it can be recorded on while it is still in its dry or unmoistened condition. Furthermore, it is not necessary to heat the blank to any particular temperature and the recording may take place at the normal ambient room temperatures.

It will be understood that the invention is not Iimited to a blank where in addition to the usual electrolytic salt or salts, there is added one or more of the special anodic ion color transducing elements above noted. Thus the method of recording according to the invention permits the manufacture and use of a relatively simple paper.

Gms.

Water 100.0 Potassium nitrate 10.0 Ethylene glycol 3.0

The saturated paper is then completely dried. In place of the potassium nitrate electrolyte, the electrolytic salt may be a nitrate or chloride of lithium, sodium, calcium, or may be a lithium sulfate, potassium sulfate, or any other well known electrolytic salt used in facsimile recording blanks, the main object being to select the salt so as to produce a finished dry blank whose surface will be free of salt crystals and which will have sufficient salt present to effect the recording as above described.

I have found that it is important to subject the stylus 14, but not the blank 15, to a local heating operation, for example 500 F. to 700 F., and in any event so that the temperature of the stylus adjacent the recording tip is not less than 350 F. This heating of the stylus at the elevated temperature mentioned continues during the recording operation, but the blank 15 as a whole is completely dry and at normal ambient room temperature.

The invention is not limited to any particular manner or locally heating the stylus 14. For example the stylus may be surrounded by a heating coil 17 which can be connected to a suitable source of heating current 18, such for example as an alternating current of relatively high frequency. Preferably, although not necessarily, the heating coil 17 may be shielded from the surface of the blank 15 so that the blank is not heated to an elevated tempera ture. In any event the heating of the stylus to at least 350 F. is important with such dry blanks where a perforated stencil record is to be made, as distinguished from a surface discoloration. If the stylus is not heated to the proper elevated temperature, unsatisfactory or irregular perforation of the blank 15 results. On the other hand, by heating the stylus locally to the above-noted elevated temperature at the same time that it is passing recording currents, I have found that it is possible to confine the perforation of the blank to each minute area beneath the point of the stylus, and the size and minuteness of the perforations for a given applied facsimile voltage are uniform over substantially the entire surface of the 'blank. The resulting stencil enables sharp and accurate reproduction of original copy by using the stencil in ordinary or well known mimeograph duplicating equipment to furnish mimeograph copies of excellent appearance and quality.

While reference has been made herein to the expression dry as applied to the recording blank, it is understood that the term dry means not purposely moistened or is in equilibrium with ambient atmospheric conditions existing at the time of recording.

Various changes and modifications [may be made in the disclosed embodiments without departing from the spirit and scope of the invention.

What is claimed is:

1. The method of making a record of electric signals such as facsimile signals using a dry paper blank containing an electrolytic salt in dry condition and free from any additional ingredients which melt during recording on the blank, which comprises passing the blank while in an unmoistened state between a pair of electrodes which define a recording point of elemental size, controlling the energizing of the electrode by signals to be recorded so as to pass recording current through the blank at said elemental area, and simultaneously controlling the heating of only one of the electrodes to maintain it at the said recording point at a temperature not less than 350 F. and with the blank free from separate preliminary heating adjacent the recording point, and being free from melting of ingredients by the recording currents.

2. The method of making a record of electric signals such as facsimile signals using a dry paper blank containing an electrolytic salt in dry condition and free from any additional ingredients which melt during recording on the blank, which comprises controlling the application of recording potentials through a stylus to selected elemental areas of the blank, and simultaneously controlling the heating of only the stylus to a temperature of not less than 350 F., and with the blank free from separate preliminary heating adjacent the recording point, and being free from melting of ingredients by the recording currents.

3. The method of making recorded perforations in a recording blank of the paper kind which includes a dry electrolytic salt and which is free from any additional ingredients which melt during recording on the blank, comprising passing the blank while in dry condition between a pair of electrodes one of which is a pointed metallic stylus, controlling the energizing of the stylus by electric signals to be recorded, and simultaneously controlling the heating of only the stylus to a temperature of approximately 500 F. to 700 F., and with the blank free from separate preliminary heating adjacent the recording point, and being free from melting of ingredients by the recording currents.

4. The method of making a stenciled record of electric signals employing a pointed stylus electrode and a dry paper blank containing an electrolytic salt in dry condition and free from any additional ingredients which melt during recording on the blank, which comprises producing scanning motion between the stylus and blank while the latter is in a dry condition, controlling the passing of electric recording current from the stylus through the successive elemental areas of the blank to perforate the blank, and simultaneously controlling the heating of only the stylus so that its recording tip is at a temperature of approximately 500 F. to 700 F., and with the blank free from separate preliminary heating adjacent the recording point, and being free from melting of ingredients by the recording currents.

5. An electrical signal recording system comprising, in combination, a pair of electrodes between which a recording paper blank is arranged to be moved which blank contains an electrolytic salt in dry condition and is free from any additional ingredients which melt during recording on the blank, said electrodes defining a recording area of elemental size, which scans the blank in response to relative scanning movement between the blank and electrodes, means to apply electric signals to one of said electrodes to cause recording currents to flow through the blank, means to heat only one of said electrodes to a temperature of not less than 350 F. while the other electrode and the entire area of the blank adjacent the recording point are unheated and at normal ambient temperature and while substantially the entire area of the blank is in a dry unheated condition and is free from any molten additional ingredients at the recording points during recording.

p 6. An electrical signal recording system comprising, in combination, a pair of electrodes one of which is a conductive platen and the other of which is a pointed recording stylus, means to support a dry paper blank containing a dry electrolytic salt on said platen which blank contains an electrolytic salt in dry condition and is free from .any additional ingredients which melt during recording on the blank, said stylus scanning the blank in response to relative movement between said platen and stylus, means to apply electric signals to said stylus to cause recording current to flow through the paper blank, means to heat said recording stylus alone and including a source of adjustable current for maintaining the recording tip of the stylus at a temperature of approximately 500 F. to 700 F. while the platen is unheated and at normal ambient temperature, and while maintaining the entire area of the paper blank adjacent the recording point in an unmoistened and unheated condition and free from any molten additional ingredients at the recording points during recording.

References Cited in the file of this patent I UNITED STATES PATENTS 2,358,839 Wagner Sept. 26, 1944 2,485,678 Tribble Aug. 21, 1947 2,662,803 Schwartz Dec. 15, 1953 2,683,111 Greig July 6, 1954 2,786,807 Schwartz Mar. 26, 1957 2,864,748 Mones Dec. 16, 1958 FOREIGN PATENTS 141,904 Australia July 2, 1951 

1. THE METHOD OF MAKING A RECORD OF ELECTRIC SIGNALS SUCH AS FACSIMILE SIGNALS USING A DRY PAPER BLANK CONTAINING AN ELECTROLYTIC SALT IN DRY CONDITION AND FREE FROM ANY ADDITIONAL INGREDIENTS WHICH MELT DURING RECORDING ON THE BLANK, WHICH COMPRISES PASSING THE BLANK WHILE IN AN UNMOISTENED STATE BETWEEN A PAIR OF ELECTRODES WHICH DEFINE A RECORDING POINT OF ELEMENTAL SIZE, CONTROLLING THE ENERGIZING OF THE ELECTRODE BY SIGNALS TO BE RECORDED SO AS TO PASS RECORDING CURRENT THROUGH THE BLANK AT SAID ELEMENTAL AREA, AND SIMULTANEOUSLY CONTROLLING THE HEATING OF ONLY ONE OF THE ELECTRODES TO MAINTAIN IT AT THE SAID RECORDING POINT AT A TEMPERATURE NOT LESS THAN 350* F. AND WITH THE BLANK FREE FROM SEPARATE PRELIMINARY HEATING ADJACENT THE RECORDING POINT, AND BEING FREE FROM MELTING OF INGREDIENTS BY THE RECORDING CURRENTS. 